JP2013010170A - Band saw blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a band saw blade whose weldability is determined to be favorable or not when subjected to endless welding.SOLUTION: On at least one straight tooth of a sawtooth group of the band saw blade, a first flank is provided ranging from the addendum of the straight tooth. On the rear side of the first flank, a second flank is provided which is connected to the bottom face of a gullet of the following tooth. An area B/an area A is a preset value or smaller where H is the depth of the gullet, G is a straight line drawn parallel to the traveling direction of the band saw blade through the bottom face of the gullet, M is a position of intersection between a parallel line K drawn parallel to the straight line G at a height of H/2.6-H/4.2 from the straight line G and the second flank, C is a vertical line vertical to the straight line G and the parallel line K from the position M of intersection, and A and B are areas between the vertical line C and a first vertical line D and between the vertical line C and a second vertical line E, respectively, when the first and second vertical lines D, E are drawn equally distant from the vertical line C and parallel to the vertical line C.

Description

  The present invention relates to a band saw blade having an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as a single saw tooth group with an appropriate pitch. More specifically, the band saw blade is welded endlessly. The present invention relates to a band saw blade manufactured by discriminating (evaluating) the ease of weldability in order to improve the quality of the endless welded part and suppress the early fracture from the welded part and to extend the life.

  Conventionally, a band saw machine has been used as a cutting machine for cutting metal workpieces. This band saw machine uses an endless welded band saw blade. As the material of the band saw blade, a so-called bimetal band saw blade in which high-speed tool steel or cemented carbide is welded or brazed as a blade to one side of a belt-like body portion of a tough alloy steel is often used. .

  The band saw blade welded in an endless shape is used by being wound around a drive wheel and a driven wheel provided in the band saw machine. Therefore, the endless band saw blade mounted on the band saw machine is driven by the saw blade guide so that the tensile stress by both the driven and driven wheels, the bending stress by both wheels and the tooth tip of the band saw blade are directed in the cutting direction with respect to the workpiece. In addition to receiving three types of twisting torsional stress, each saw blade in the band saw blade receives impact and vibration every time it bites into the workpiece. That is, the band saw blade is used under severe conditions. Accordingly, the body portion of the band saw blade may be fatigued and reach its life.

  By the way, the endless band saw blade used for the band saw machine is configured in an endless shape by cutting a long band saw blade to a desired length and welding the cut ends. Therefore, in order to extend the life of the endless band saw blade, the welding quality of the welded portion (endless welded portion) is an important factor. For example, if there is a level difference in the endless welded part, the cut part may be scratched every time the band saw blade makes a round, or tooth cracks may occur before and after the welded part. In addition, if there is a metallic defect in the endless weld, it may cause breakage at an early stage. Needless to say, no matter how much the material and tooth profile of the band saw blade are improved, if there is a defect in the endless welded portion, the improvement effect cannot be obtained.

  By the way, as is well known, the band saw blade has an appropriate number of straight teeth and an appropriate number of left and right set teeth, and between each of the saw teeth, chips generated by cutting the workpiece are temporarily stored. A galette (chip pocket) is formed for storage. The deepest part of this galette may be called a tooth bottom. This tooth bottom part is the part where the band width dimension of the band saw blade is the smallest, and the part where the stress is concentrated most. Therefore, fatigue fracture in the band saw blade often occurs at the root portion.

  Therefore, it has been proposed that endless welding is performed at the flank portion of the saw blade while avoiding the bottom portion of the galette in the band saw blade (see Patent Document 1). In addition, there exist patent documents 2-4 as prior art literature considered to be related to this invention.

EP0531879B1 publication JP-A-6-718 US Pat. No. 4,292,871 Japanese Patent No. 4464473

  The configuration of the saw blade described in Patent Document 1 includes a relief surface connected from the tooth tip of the saw tooth to the root (bottom surface) of the galette in the subsequent tooth on the rear side of the saw tooth. In other words, the relief angle of the flank is constant. Therefore, when the one end side and the other end side of the long band saw blade are simply brought into contact with each other, the flank face may be continuous.

  However, in the case of endless welding of the one end side and the other end side cut by the band saw blade, flash butt welding is generally used in many cases. Therefore, at the time of flash butt welding, when the end faces of each other are lightly contacted and energized, the minute protrusions on the end faces come into contact with each other and are rapidly heated and melted, resulting in sparks scattered around the outer periphery of the weld. Furthermore, when both end surfaces are brought close to each other, the other microprotrusions come into contact with each other and are melted and scattered. Then, the oxides are extruded and welded by pressurizing in a direction in which the entire weld surfaces butted together face each other when they reach the melting point.

  That is, when endless welding is performed on the portion of the flank surface of the saw blade in the band saw blade, the metal is removed from the welded portion by flash butt welding, and a step portion is generated on the flank surface of the saw blade.

  It is also possible to cut the flank portion of the saw blade in consideration of the generation of the stepped portion. However, in this case, it is necessary to cut so that the other end side (the bottom side of the gallet) is higher than the one end side (the tooth tip side of the saw tooth) with which the band saw blade cut to perform endless welding is abutted. There is a problem that it is difficult to set the cutting positions on both ends of the band saw blade.

  By the way, in order to reduce the stepped portion when the endless welding of the band saw blade is performed, it is only necessary to reduce the clearance angle of the flank in the saw tooth. However, if the clearance angle in the saw blade is reduced, a new problem arises that the galette depth of the subsequent tooth is reduced. Therefore, if the clearance angle of the flank face of the saw blade is increased so that the galette depth does not decrease, the step difference of the step portion generated at the endless welding at the flank portion increases and the tooth angle of the tooth tip of the saw blade decreases. Thus, there is a problem that the strength of the tooth tip decreases.

  Therefore, as in the configuration of the saw blade described in Patent Document 3, the clearance angle is larger than the clearance angle of the first clearance surface on the rear side of the first clearance surface from the tooth tip of the saw blade, and the rear side When the second flank is connected to the bottom surface of the galette in the succeeding tooth, the tooth angle of the tooth tip in the saw tooth can be increased and the area of the galette can be increased. That is, it is desirable to improve the strength of the tooth tip in the saw blade and increase the galette area.

  However, in the above configuration, when endless welding of the band saw blade is performed, if the bottom (bottom) portion of the galette is avoided, the endless portion of the first flank or the second flank of the saw blade is endless. Welding will be performed. However, the first flank is a position close to the tooth tip of the saw tooth and is not a preferable position for performing endless welding. Since the second flank has a large flank angle, the step difference of the step portion generated when endless welding is performed is not desirable.

  By the way, endless welding of the band saw blade is performed at the position of the second flank when avoiding the first flank and the bottom of the galette near the tooth tip of the saw tooth. In performing endless welding at the position of the second flank, when cutting a long band saw blade, the cutting is not always accurate at the center of the second flank. Therefore, when the cut surfaces on the one end side and the other end side of the cut band saw blade are abutted, when the cut surface is properly aligned, the cut surface on the one end side is larger than the cut surface on the other end side, Conversely, it may become smaller.

  Then, when endless welding is performed by flash butt welding with both end sides of the band saw blade faced together, for example, if the cross-sectional area on the other end side is larger than the cross-sectional area on one end side, There is little rise in temperature on the end side, and insufficient melting may occur, resulting in metallographic defects. When endless welding of the band saw blade is performed by flash butt welding, the molten metal at both ends is pushed out, so that the stepped portion of the flank surface after welding becomes large and the extruded metal is removed by polishing work with a grinding wheel There is a need. At this time, if the clearance angle of the flank is large, it is necessary to bring the polishing wheel closer to the bottom side of the galette, which makes the polishing operation difficult, and in some cases, the polishing wheel contacts the tip of the adjacent subsequent tooth. The tooth tip may be damaged.

  Therefore, the present invention provides the second flank portion of the saw blade in which a second flank surface connected to the bottom surface of the galette in the subsequent tooth is formed on the rear side of the first flank surface from the tooth tip in the saw blade. When endless welding of the band saw blade is performed, the ease of endless welding can be determined by satisfying certain conditions of the second flank. According to this determination method, the conventional method as described above can be performed. This is based on knowledge that can solve the problem.

  The present invention has been made in view of the conventional problems as described above, and is a band saw blade having an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as a single saw tooth group at an appropriate pitch. Then, at least one straight tooth in the sawtooth group is provided with a first flank from the tip of the straight tooth, and behind the first flank, in the succeeding tooth behind the straight tooth A second flank is connected to the bottom surface of the galette, and the end angle of the second flank is set to be less than 44 ° in order to perform endless welding on the second flank. Is.

  A band saw blade having an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as one saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the straight tooth. A first flank from the tip of the tooth and a second flank formed of a concave curved surface connected to the bottom surface of the galette in the succeeding tooth on the rear side of the straight tooth on the rear side of the first flank. In order to perform endless welding on the second flank, the center position of the second flank is set outside the galette.

  A band saw blade having an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as one saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the straight tooth. A first flank from the tip of the tooth and a second flank connected to the bottom surface of the galette in the succeeding tooth behind the straight tooth on the rear side of the first flank. A third flank is provided between the flank 1 and the second flank, and in order to perform endless welding on the third flank, the clearance angle of the third flank is 0 ° or more. The angle is set to be less than 44 °.

  The band saw blade is welded endlessly on the second flank.

  A band saw blade having an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as one saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the straight tooth. A first flank from the tip of the tooth, and a second flank connected to the bottom surface of the galette of the succeeding tooth on the rear side of the straight tooth on the rear side of the first flank. A straight line when a straight line parallel to the traveling direction of the band saw blade is drawn through the bottom surface of the galette is defined as G, and a range from H / 2.6 to H / 4.2 from the straight line G. An intersection position with the second flank when a parallel line K parallel to the straight line G is drawn at a height of M is defined as M, and a vertical line perpendicular to the straight line G and the parallel line K is defined from the intersection position M. C, and the first and second equidistant from the vertical line C and parallel to the vertical line C When the straight lines D and E are drawn, an area surrounded by the vertical line C, the second flank, the first vertical line D and the straight line G is A, and the vertical line C, the flank, and the second Assuming that the area surrounded by the vertical line E and the straight line G is B, area B / area A is equal to or less than a predetermined value set in advance.

  In the band saw blade, the offset distance from the vertical line C to the first and second vertical lines D and E is in a range of 0.1 mm to 1.56 mm.

  In the band saw blade, the value B / A of the area B / area A is in the range of 102% to 292%.

  In the band saw blade, the pitch between the straight tooth and the subsequent tooth is a maximum pitch.

  Further, in the band saw blade, a galette area between the straight tooth and the succeeding tooth is larger than a galette area of the minimum pitch in the saw tooth group.

  Further, in the band saw blade, the number of saw teeth between the straight teeth is 3 or less.

  According to the present invention, the straight tooth for endless welding in the band saw blade includes the first flank from the tooth tip of the straight tooth, and the rear posterior tooth on the rear side of the first flank. A second flank face connected to the bottom surface of the galette is provided, and in order to perform endless welding on the second flank face, the flank angle of the second flank face is set to be less than 44 °. Therefore, the strength of the tooth tip can be improved and the area of the galette can be increased. In addition, the stepped portion that tends to occur in the endless welded portion can be reduced, and the amount of polishing by the polishing operation after welding can be suppressed to be small, and the conventional problems as described above can be solved.

It is explanatory drawing which shows the structure of the band saw blade which concerns on the 1st Embodiment of this invention. It is explanatory drawing of the method of determining (evaluating) the quality of the saw-tooth weldability at the time of endless welding of a band saw blade. It is explanatory drawing which applied the specific numerical value to the said determination method. It is explanatory drawing which shows the structure of the band saw blade which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the structure of the band saw blade which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which showed the specific numerical value to the sawtooth. It is explanatory drawing which shows the change of offset distance when the height position of a parallel line is variously changed in the sawtooth shape shown in FIG. It is explanatory drawing which shows the change of the evaluation value (determination value) of weldability when the height position of a parallel line and offset distance in each sawtooth shape shown to FIGS. It is explanatory drawing which made the table | surface shown in FIG. 26 into the graph.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a band saw blade 1A according to an embodiment of the present invention is swung out to the left side with a straight tooth T1 like a general band saw blade. A plurality of left set teeth T2, T4, T6 and a plurality of right set teeth T3, T5, T7 which have been subjected to (crushing) are provided as one sawtooth group.

  The sawtooth group is a group in which a desired tooth tip pitch pattern group (tooth tip pitch group) and a desired clam pattern group (claw pattern group) are combined, and is repeated in one long band saw blade. This is the longest pattern to be placed. When the tooth tip pitch pattern group is included in the set pattern pattern group, the length of the set pattern pattern and the length of the saw tooth group are the same.

  Incidentally, the set pattern of the band saw blade 1A shown in FIG. 1 includes straight teeth T1, left set teeth T2, right set teeth T3, left set teeth T4, right set teeth T5, left set teeth T6 and right set teeth T7. It is a clam pattern consisting of seven teeth, and this clam pattern is repeated. The tooth tip pitch pattern is a pitch pattern of each pitch 8.15 mm, 7.45 mm, 6.5 mm, 6.4 mm, 6.8 mm, 8 mm, and 8.5 mm between the saw teeth T1 to T7. The pattern is repeated. The clam pattern and the pitch pattern are both equal in length and 51.8 mm.

  The angle of the saw teeth T1 to T7 is set to 7 °. The first flank RF1 from the tooth tip TE in each of the saw teeth T1 to T7 is set to 25 °, and the first flank RF1 of the saw tooth T1 has the galette GA2 in the rear succeeding tooth T2. A second flank RF2 connected to the tooth bottom (bottom) TB is provided. The clearance angle of the second clearance surface RF2 at the straight tooth T1 is set to 40 °, and the clearance angle of the second clearance surface RF2 at each of the saw teeth T2 to T7 is set to 55 °.

  The second flank RF2 of each of the saw teeth T1 to T7 and the tooth bottom TB of each of the galettes GA1 to GA7 are connected by an arc. That is, the saw teeth T1 to T7 are followed by arcs having radii of 1.63 mm, 1.49 mm, 1.3 mm, 1.28 mm, 1.36 mm, 1.6 mm and 1.7 mm, respectively, as shown in FIG. The galettes GA2 to GA7 and GA1 of the teeth T2 to T7 and T1 are connected to the tooth bottom TB, respectively. The tooth bottom TB of the galette GA1 of the saw tooth (straight tooth) T1 is provided with a flat portion having a length of 0.85 mm in the traveling direction of the saw blade 1A. The tooth bottom TB of the gallet GA2 of T2 is formed in an arc having the radius R = 1.63 mm. As shown in FIG. 1, the flat portions of 0.745 mm, 0.65 mm, 0.64 mm, 0.68 mm, and 0.8 mm are formed on the bottoms TB of the galettes GA3 to GA7 of the other saw teeth T3 to T7. Is provided.

Furthermore, the depth of each galette GA1-GA7 of each said sawtooth T1-T7 is formed in 4.25mm, 4.075mm, 3.725mm, 3.25mm, 3.2mm, 3.4mm and 4mm, respectively. . When the calculating the area of each numerical values based on each gullet ^{GA1~GA7, 21.79mm 2, 18.98mm 2,} 16.74mm 2, 12.74mm 2, 12.36mm 2, 13.95mm 2 and 19.31 mm ² .

  When the band saw blade 1A having the above-described configuration is welded endlessly by flash butt welding, the tooth bottoms (bottom surfaces) TB of the galettes GA1 to GA7 of the respective saw teeth T1 to T7 are avoided, and the clearances of the respective saw teeth T1 to T7 are obtained. As a method for determining the ease of welding, the following determination method was adopted for performing endless welding on the surface. Even if endless welding is performed on the flank portion of each of the saw teeth T1 to T7, the first flank RF1 is close to the tooth tip TE. It is desirable to avoid one flank. Therefore, the ease of endless welding is determined at a portion corresponding to the second flank RF2. In other words, when there are a plurality of flank faces as the flank face of the saw blade, the ease of endless welding is determined at a portion corresponding to the other flank face except for the first flank face RF1. is there.

  FIG. 2 schematically shows the relationship between the saw blade T2 and the saw blade T3. The first clearance angle of the saw blade T2 is β °, the second clearance angle is α °, and the tooth tips of the saw blades T2 and T3. The pitch is P, and the depth of the galette GA3 of the saw tooth T3 as the succeeding tooth of the saw tooth T2 is H. Further, let R be the radius of the arc connecting the second flank RF2 and the root TB of the galette GA3, and the traveling direction of the band saw blade through the bottom (bottom) TB of the galette GA3 (left-right direction in FIG. 2). G) is a straight line when a straight line parallel to) is drawn. Then, at a desired height position from the straight line G, for example, at a height position in the range of H / 2.6 to H / 4.2 (illustrated as H / 4 in FIG. 2), the straight line G When a parallel line (cross line) K is drawn, the intersection position with the second flank RF2 is defined as M, and the perpendicular vertical perpendicular to the straight line G and the parallel line K from the intersection position M. The line is C.

  If the height position of the parallel line K for obtaining the intersection position M is small, it is not desirable because the intersection position M is close to the tooth bottom TB of the galette GA. If the height position is large, the first flank face is not desirable. It is not desirable because it is close to RF1. Therefore, it is desirable to set it as H / 2.6-H / 4.2.

Further, the first and second parallel to the vertical line C within the range of the travel direction of the second flank and the distance (offset amount) L equal to the travel direction of the band saw blade from the vertical line C. It is desirable to draw vertical lines D and E. However, the positions of the vertical lines D and E are not necessarily within the range of the traveling direction of the second flank. The area (area between the vertical lines C and D) surrounded by the vertical line C, the second clearance surface RF2, the first vertical line D, and the straight line G is defined as Amm ² . Further, an area surrounded by the vertical line C, the second flank face RF2, the second vertical line E, and the straight line G (area between the vertical lines C and E) is defined as Bmm ² . When the ratio between the area B and the area A, that is, the value B / A (determination value, evaluation value) of the area B / the area A is equal to or smaller than a predetermined value that is obtained in advance or experimentally (set), It is determined that the weldability is good.

  Incidentally, when the above condition is applied to each of the saw teeth T1 to T7 in the band saw blade 1A and the offset amount (distance) L is set to L = 1 mm, the areas A, B and B / A are specifically calculated. Then, as shown in FIG.

  Then, in the state before the straight tooth T1 and the left and right set teeth T2 to T7 are distributed (climbing out), cutting is performed at each second flank face RF2, and the cut surfaces are abutted to each other. When the endless welding (flash butt welding) was performed under the welding conditions and the test was performed, the size of the stepped portion on the second flank RF2, the amount of bulging of the meat in the welded portion, and the polishing work for removing the portion are easy. When comprehensively evaluating (discriminating and judging) in consideration of the properties and the like, the endless welding at the portion of the second flank RF2 in the sawtooth T1 was the best. The value B / A (evaluation value) of area B / area A at the sawtooth T1 at this time is 240%, and the value B / A (evaluation value) of area B / area A of the other sawtooth T2 to T7 is respectively 432%, 503%, 517%, 484%, 389%, and 363%, which were large values compared to 240%.

  That is, when the value B / A (determination value) of area B / area A is 363% or more, comprehensive evaluation of weldability of endless welding is not good, and when value B / A is 240%, weldability is good. I found out that Here, the clearance angle of the second clearance surface RF2 at the straight tooth (saw tooth) T1 is 40 °, and the clearance angle of the second clearance surface RF2 at the other saw teeth T2 to T7 is 55 °. In each of the saw teeth T2 to T7, if the radius R of the arc connecting the tooth bottom TB of the galette GA and the second flank RF2 is different, the value B / A of the area B / area A is different, and the radius R As B becomes larger, the value B / A becomes smaller. However, when the saw blade T1 and the saw blade T7 are compared, the value B / A is greatly different because the relief angle of the second relief surface RF2 is different from 40 ° and 55 °.

Therefore, as shown in FIG. 3, the value B / A is obtained by gradually increasing the clearance angle α of the second flank RF2 at the saw tooth T1, and endless welding is performed on the second flank RF2 under the same conditions. An experiment was conducted to determine whether the weldability was good. Here, when α = 40 °, A = 0.60 mm ² , B = 1.44 mm ² , and the value B / A was 240%. Accordingly, when the areas A and B are calculated by gradually increasing the clearance angle α,
α = 42 °, A = 0.62 mm ² , B = 1.51 mm ² , B / A = 244%
α = 43 °, A = 0.63 mm ² , B = 1.55 mm ² , B / A = 246%
α = 44 °, A = 0.63 mm ² , B = 1.59 mm ² , B / A = 252%
α = 45 °, A = 0.64 mm ² , B = 1.63 mm ² , B / A = 255%
α = 50 °, A = 0.68 mm ² , B = 1.84 mm ² , B / A = 271%
It is. When the weldability on the second flank RF2 is comprehensively evaluated in the same manner as described above, the value B / A = 246% at α = 43 ° was good, but the value B / A was obtained at α = 44 °. When A = 252%, it was defective.

  Therefore, in the band saw blade, the clearance angle α of the second flank RF2 at the saw tooth T1 for performing endless welding is less than 44 °, and the value B / A of the area B / area A when the distance L = 1 mm is It is desirable that it is 246% or less.

  When the distance L is variously changed to, for example, 0.1 mm, 0.3 mm, 0.5 mm, etc., the value B / A varies depending on the value of the distance L. Therefore, in order to determine (evaluate) the quality of weldability when performing endless welding of the band saw blade, the value B / A is experimentally obtained in advance corresponding to the value of the distance L, and a predetermined value B / A is determined. It is desirable to set the value in advance. By the way, the minimum value of the value B / A is 100%. That is, when a flank face (flank angle is 0 °) parallel to the traveling direction of the band saw blade (left and right direction in FIG. 2) is formed at the intersection position M, for example, as a third flank face, When the distance L is small, the area B = area A and the value B / A = 100%.

  By the way, in order to cut a long band saw blade to a desired length and connect it in an endless manner, it is also possible to previously form the third flank as a cutting point on a desired straight tooth of the sawtooth group in the band saw blade. It is. In this case, flash butt welding is performed on the third flank. Therefore, in consideration of endless welding, the flank angle of the third flank is preferably 0 ° or more and less than 44 °. It will be a thing.

  As described above, the third flank is formed in advance on the desired straight tooth of the sawtooth group in the band saw blade as a place where endless welding is performed, so that the flash as endless welding is always performed at the position of the third flank. Since butt welding is performed, the weldability of endless welding in the band saw blade can always be kept good. It is desirable that the length of the third flank is not less than the length that allows for the length (welding allowance) that disappears by flash butt welding.

  As already understood, in the band saw blade 1A, the second flank face RF2 of at least one straight tooth T1 in the sawtooth group is set to be less than 44 °, and the second flank face RF2 in the straight tooth T1 is endless. By making the welding location for performing welding, the weldability of the endless welding of the band saw blade 1A can always be maintained satisfactorily.

  FIG. 4 shows a band saw blade 2A according to the second embodiment. In the band saw blade 2A, components having the same functions as those of the band saw blade 1A are denoted by the same reference numerals, and redundant description is omitted. This band saw blade 2A has eight teeth of straight teeth T1, left set teeth T2, right set teeth T3, left set teeth T4, straight teeth T5, right set teeth T6, left set teeth T7 and right set teeth T8 as saw teeth. This is a configuration provided as two sawtooth groups.

  Since the configuration of each of the saw blades T1 to T8 in the band saw blade 2A is similar to the configuration of the saw blades described in the above-mentioned patent document 4, each of the saw blades T1 to T8 is a first one from the tooth tip TE. And a second flank face RF2 connected to the root (bottom face) TB of the galette of the subsequent tooth. In addition, a tooth missing protector in which a third flank face RF3 of a flank face parallel to the traveling direction of the band saw blade 2A is formed between the first flank face RF1 and the second flank face RF2 is provided. is there. In addition, since this 3rd flank RF3 is adjoining to the tooth top TE, it is not desirable to make this 3rd flank RF3 the welding location of endless welding.

  In the band saw blade 2A, the gallet depth H of each of the saw teeth T1 to T8 is set to 3 mm, and the clearance angle of the second flank RF2 at each of the saw teeth T2 to T4 and T6 to T8 is set to 50 °. is there. The second flank RF2 of the straight teeth T1 and T5 has a flank angle of 29.1 °, which is less than 44 °, with the position of the second flank RF2 as a welding location for endless welding. It is set. The second flank RF2 in each of the saw teeth T1 to T8 and the tooth bottom TB of each galette are connected by an arc having a radius R = 1.7 mm.

  In order to determine (evaluate) the weldability of the endless welding at the second flank RF2 in each of the saw blades T1 to T8 in the band saw blade 2A, the area B in the same evaluation method as in the case of the band saw blade 1A, When the area A was calculated and the value B / A was obtained, the values B / A of the straight teeth T1 and T5 were 219% and 246% or less.

  By the way, in the said structure, it is set as constant galette GA2 and GA6 with the depth H = 3mm and constant gullet GA2 and GA6 with the circular root bottom TB with the radius R = 1.7mm on the scooping surface of the subsequent teeth T2 and T6. By using the second flank RF2 as a straight line in contact with the tooth bottom TB from the third flank RF3, the flank angle of the second flank RF2 is 29.1 °. As described above, the value B / A is 219%.

  As apparent from the above, in the band saw blade 2A, the interval dimension between the straight tooth T1 and the straight tooth T5 is a structure including three teeth of left and right set teeth T2, T3, T4 or T6, T7, T8. There is a small value of 29 mm. That is, a plurality of (two teeth) straight teeth T1 and T5 that can be endless welding positions exist in one sawtooth group. Therefore, one end side of the band saw blade can be set as, for example, a straight tooth T1, and the other end side can be set as a straight tooth T5. When the band saw blade is welded in an endless manner, a diameter error with respect to a predetermined diameter is reduced. . Therefore, the amount of adjustment of the driven wheel when it is hung on the drive wheel and driven wheel in the band saw machine may be small.

Then, in the above arrangement, the gullet area of the subsequent tooth T2, T6 straight teeth T1, T5 is a 14.21Mm ^2, greater than gullet area 11.00 mm ² of minimum pitch 6.2mm of the band saw blade 2A Is. Therefore, the galette area is not excessively reduced, and the cutting efficiency is not affected.

  That is, according to the configuration of the band saw blade 2A, an endless welded portion is provided in a gallet having a maximum pitch of 8.3 mm in one saw tooth group, thereby suppressing the influence due to the reduction of the galette area, and The value B / A can be made smaller than the value B / A of other saw blades.

  FIG. 5 shows a band saw blade 3A according to the third embodiment. In the band saw blade 3A, components having the same functions as those of the band saw blades 1A and 2A are denoted by the same reference numerals, and redundant description is omitted.

  The band saw blade 3A has almost the same configuration as that of the band saw blade 2A. The difference is that the second flank RF2 at the straight teeth T1 and T5 is formed in an arc shape. . The radius R of the arc of the second flank RF2 is 6 mm and is set to be larger than the galette depth H = 3 mm. That is, the center position of the arc of the second flank RF2 is set outside the galette.

  In the above configuration, in order to determine (determine) the weldability of the endless welding at the second flank RF2 at the straight teeth T1 and T5, the areas B and A in the same evaluation method as the case of the band saw blade 1A are used. When the value B / A was calculated, the value B / A of the straight teeth T1 and T5 was 210%, which was 246% or less. This band saw blade 3A also has the same effect as the band saw blade 2A.

  As understood from the above description, when the long band saw blade is cut and welded in an endless manner, as described above, the clearance angle of the second flank RF2 at the straight tooth T1 should be less than 44 °. When the second flank RF2 is a concave arcuate surface, the quality of the endless welding is judged good by making the radius 6 mm large so that the center of the arcuate surface is located outside the galette. It turns out to be better. In this case, according to the discrimination method (evaluation method) described above, the value B / A of the ratio between the area B and the area A described above is 246% or less, and it can be determined as good.

  By the way, it has been difficult to numerically evaluate the quality of weldability when the band saw blade is welded endlessly. However, as in the discrimination method (evaluation method) as described above, the portion where the endless welding of the band saw blade is performed is a flank face on the straight tooth, and a flank face (first face) connected to the bottom face (tooth bottom) of the gallet on the subsequent tooth. 2). Then, the position of the flank to be welded (position of the vertical line C) is specified, and the areas A and B before and after a distance (width) L equal to the traveling direction of the band saw blade centered on the position to be welded ( By calculating B) on the front side in the traveling direction and A) on the rear side, it is confirmed whether or not the value B / A of the area B / area A is equal to or less than a predetermined numerical value obtained experimentally in advance. The weldability can be evaluated (discriminated).

  Therefore, by setting the shape of the straight tooth in the band saw blade according to the evaluation method (discrimination method), a band saw blade with good weldability of endless welding can be obtained.

  By the way, there are various configurations of the saw blade in the conventional band saw blade, and various configurations of the saw blade are assumed. Therefore, the above-described evaluation method (discrimination method) is applied to conventional actual saw blades and assumed saw blades, and the weldability of endless welding is verified for saw blades of various configurations.

  FIG. 6 shows the tooth profile described in Patent Document 3, with a tooth tip pitch of 6.35 mm, a rake angle of 4 ° to 7 ° to 5.5 °, a first clearance angle of 25 ° to 31 ° to 28 °, a second angle. Clearance angle 53 ° to 61 ° to 57 °, galette depth H (0.46 to 0.56) × pitch to 0.51 × 6.35 = 3.24 mm, root R (0.38 to 0.48) ) X Drawing from 0.43 x 3.24 = 1.39 mm from the depth of the galette and 0.1 x 6.35 = 0.635 mm from the root straight line length 0.1 x pitch or more It is. Here, the distance in the horizontal direction from the intersection of the tooth bottom straight portion and the tooth bottom R 1.39 mm on the second flank side to the intersection of the first flank and the second flank is 1.99 mm. If numerical determination (evaluation) of the weldability of endless welding is attempted within this range, it is difficult to actually determine where the intersection of the root straight part and the bottom R on the flank side is.

Therefore, when a vertical line is drawn with reference to the point where the straight line offset from the tooth base to the tooth tip side by 0.03 mm and the tooth bottom R on the flank side intersect, and further in the running direction and offset by 2 mm to the tooth tip side The vertical position C was taken as the center position. In this case, the position where the vertical line C and the second flank intersect each other is 0.82 mm from the tooth bottom and is substantially equal to H / 4. Therefore, the area A in L = 1 mm before and after the vertical line C, and calculates a B, and a surface area B = 1.55 mm ² in area A = 0.30 mm ^2, and a value B / A = 517% . In this case, since it exceeds 246%, the determination is NG (difficult weldability).

7 to 9 show a conventional sawtooth shape, the clearance angle is constant at 30 °, and the values of the galette depth H and the root R are different. In the case of the above shape, area A = 0.46 mm ² , area B = 1.04 mm ² , value B / A = 226% (FIG. 7): area A = 0.56 mm ² , area B = 1.14 mm ² , Value B / A = 204% (FIG. 8): Area A = 0.59 mm ² , Area B = 1.16 mm ² , Value B / A = 197% (FIG. 9), and judgment is G (easy to weld) . That is, the clearance angle is 30 ° which is less than 44 °.

10 to 12 show a conventional known sawtooth shape, and the dimensions of each element of the sawtooth are as shown in FIGS. In this case, in the sawtooth of FIG. 10, the area A = 0.29 mm ² , the area B = 1.50 mm ² , the value B / A = 517%, and exceeds 246%, so the determination is NG. 11, the area A = 0.45 mm ² in the case of FIG. 12, the area B = 1.73 mm ^2, the value B / A = 384%: area A = 0.49 mm ^2, the area B = 1.78 mm ^2, the value B / A = 363%, respectively exceeding 246%, so it is NG.

  FIGS. 13 and 14 show the case where the second clearance angle is 43 ° and 44 ° in the configuration (shape) of the saw blade shown in FIG. 3, and FIG. 15 shows the straight tooth T1 of the first embodiment. This is the case. Therefore, as already described, the evaluation in the configuration of FIG. 13 is G, the evaluation in the configuration of FIG. 14 is NG, and the evaluation in the configuration of FIG.

16-18 is the case of the said sawtooth structure shown in FIG. 4, Comprising: In the sawtooth of FIG. 17, when the clearance angle of a 2nd flank is 50 degrees with a tooth-tip pitch of 8.3 mm. Was assumed. In Figure 16 and 17, the area A = 0.32 mm ^2, the area B = 1.35 mm ^2, the value B / A = 422%, in FIG. 18, the area A = 0.47 mm ^2, the area B = 1 0.03 mm ² , value B / A = 219%, the evaluation of the saw blade in FIGS. 16 and 17 is NG, and the evaluation of the saw blade in FIG.

FIG. 19 shows a case of a maximum pitch 8.3mm 5, the area A = 0.51 mm ^2, the area B = 1.07 mm ^2, evaluated at the value B / A = 210% is G. 20 and 21 is a conventional sawtooth, and when the area A = 0.45 mm ^2, is evaluated by the area B = 1.46 mm ² with a value B / A = 324% of NG, the area A = 1.20 mm ² , the area B = 1.87 mm ² , the value B / A = 156%, and the evaluation is G.

22 assumes that the clearance angle of the second flank is as large as 50 °, but the radius R of the arc connecting the tooth bottom TB of the galette GA and the second flank is as large as 5 mm. It is shown. In this case, the area A = 1.17 mm ^2, the area B = 2.21 mm ^2, next to the value B / A = 189%, becomes less than 246%. Therefore, the evaluation in this case is G. Here, the reason why the determination was G because the value B / A = 189% despite the clearance angle of the second flank being 50 ° and larger than 44 ° is shown in FIG. Since the radius is approximate to the radius R = 6 mm in the case of the straight tooth T1 and is a large radius, the areas A and B when the determination (evaluation) is performed are in the range of the arc portion having a large radius (a portion having a small curvature). It can be considered that it is inside. Therefore, in order to improve the weldability of the endless welding, it is desirable that the radius R connecting the second flank face of the saw blade and the tooth bottom TB of the galette GA is 5 mm or more.

FIG. 23 shows the case where the second flank of the saw blade is formed into an arc having a radius R = 3.5 mm. In this case, the area A = 1.04 mm ² , the area B = 2.78 mm ² , the value B / A = 267%, and the evaluation is larger than 250% as NG. In this case, it can be considered that the radius of the arc as the second flank is 3.5 mm and the curvature of the second flank is large. Therefore, when the second flank has a circular arc configuration, it is desirable to increase the radius of the second flank, for example, R = 5 mm or more in order to reduce the curvature.

FIG. 24 shows a case where the clearance angle of the flank of the saw blade is set to 30 ° and 44 ° or less, and the flank and the bottom of the galette are connected by an arc having a radius R = 10 mm. In this case, since the clearance angle of the flank is small and the radius is large as R = 10 mm, the area A = 1.71 mm ² , the area B = 2.29 mm ² , and the value B / A = 134%. is there.

  The evaluation method (determination) of the weldability of endless welding for each sawtooth shape shown in FIGS. 6 to 24 is the evaluation method shown in FIG. This is a case where the height position up to a certain) is H / 4, and the offset distance to the first and second vertical lines D and E offset from the vertical line C, that is, the distance L is 1 mm. Therefore, the case where the height position of the parallel line (cross line) K was changed variously and the case where the offset distance, that is, the distance L was changed variously were examined.

  Here, the case where the height position and the offset distance of the cross line (parallel line) K were applied to the sawtooth shape shown in FIG. 6 as the sawtooth shape was examined. The sawtooth shape is not limited to the sawtooth shape shown in FIG. 6, and may be applied to other sawtooth shapes.

  In the sawtooth shape shown in FIG. 6, the height position of the parallel line K is H / 4 (0.81 mm), H / 3.5 (0.93 mm), H / 3 (1.08 mm), H / 2. .7 (1.20 mm) and H / 2.6 (1.25 mm) are applied. Then, from the contact O between the root straight line portion (0.635 mm) and the second flank radius R = 1.39 mm, the height position of each parallel line K is 0.81 mm (H / 4),. Crossing position with second flank at 93 mm (H / 3.5), 1.08 mm (H / 3), 1.20 mm (H / 2.7), 1.25 mm (H / 2.6) The distances from M to the vertical line C are 1.28 mm, 1.36 mm, 1.46 mm, 1.53 mm and 1.56 mm, respectively, as shown in FIG. Therefore, the maximum offset distance L from the vertical line C is 1.28 mm in the case of H / 4 (0.81 mm).

  Here, when the height position of the parallel line K is set to H / 4 and the offset distance L is set to 1.28 mm, the above-described areas A and B are obtained and the value B / A is calculated as shown in FIG. Looking at the column of H / 4 and offset 1.28 mm in FIG. 26, the saw blade of FIG. 13 whose evaluation was G was 345%, whereas that of the saw blade of FIG. 23 whose evaluation was NG. In this case, the value is 321%, and the numerical value in the case of the saw blade shown in FIG. 23 is smaller than that in the case of the saw blade shown in FIG. 13, which contradicts the case of H / 4 and offset 1.0 mm. That is, evaluation (determination) is impossible at H / 4 and offset of 1.28 mm.

  Next, when the position of the parallel line K is set to H / 4 and the offset distance L is set to 1.1 mm in the same manner as described above, the value B / A is calculated in the same manner. In the case of the saw blade shown in FIG. In the case of the saw blade shown in FIG. Further, when the height position of the parallel line K is set to H / 4 and the offset distance L is reduced to 0.1 mm to obtain the value B / A, as shown in FIG. 26, in the case of the sawtooth shape shown in FIG. Was 109.6%, and it was 110.2% in the case of the sawtooth shape shown in FIG. In this case, it can be determined because it is consistent with H / 4 and an offset of 1.0 mm.

  That is, when the height position of the parallel line K is H / 4, the weldability can be judged (evaluated) in the range of the offset distance L = 0.1 mm to 1.0 mm, although the value B / A is different. It is. It is also possible to make the offset distance L smaller than 0.1 mm. However, if the offset distance L is smaller than 0.1 mm, a delicate determination is made. Therefore, it is not desirable to make the offset distance L smaller than 0.1 mm.

  As already understood, there is an appropriate range in the relationship between the height position of the parallel line K (for example, H / 4) and the range of the offset distance L, and welding is performed at the offset distance L within the appropriate range. The value B / A (%) for evaluating (determining) the sex is different for each offset distance L. Therefore, the value B / A is set in advance to an experimentally determined value corresponding to the height position of the parallel line K to be applied and the offset distance L.

  As described above, since the range of the offset distance L that can be applied corresponding to the height position (for example, H / 4) of the parallel line K is determined, the height position of the parallel line K and the offset distance L In order to obtain the relationship, various height positions (H / 4.3 to H / 2.5) are applied to the sawtooth shapes shown in FIGS. The results of obtaining the value B / A by applying various offset distances L are as shown in FIG.

  Here, when the height position of the cross line (parallel line) K is H / 4.3, it is shown in FIG. 23 rather than the value B / A (110.3%) in the case of the sawtooth shape shown in FIG. Since the value B / A (110.1%) of the sawtooth shape becomes small, the determination of weldability becomes impossible. That is, it cannot be determined if the number of denominators for obtaining the height position is 4.3 or more. The following is a summary.

(1) Cannot be determined if the cross line H / 4.3 and the denominator is 4.3 or higher.

(2) In the cross line H / 4.2, determination can be made with an offset amount of 0.1 mm.

  Judgment at this time is easily weldable at 110.1% or less, and difficult to weld at 110.5% or more.

(3) In the cross line H / 4, determination can be made in the range of offset amount from 0.1 mm to 1.0 mm.

  When the offset amount is 0.1 mm, the weldability is easy at 109.6% or less, and weldability is difficult at 109.9% or more.

  When the offset amount is 1.0 mm, the weldability is easy at 246% or less, and weldability is difficult at 252% or more.

(4) In the cross line H / 3.5, the offset can be determined in the range of 0.1 mm to 1.2 mm.

  When the offset amount is 0.1 mm, the weldability is easy at 108.3% or less, and weldability is difficult at 108.7% or more.

  When the offset amount is 1.2 mm, the weldability is easy at 280% or less, and weldability is difficult at 288% or more.

(5) In the cross line H / 3, the offset can be determined in the range of 0.1 mm to 1.46 mm.

  When the offset amount is 0.1 mm, the weldability is easy at 107.1% or less, and weldability is difficult at 107.4% or more.

  When the offset amount is 1.46 mm, the weldability is easy at 292% or less, and weldability is difficult at 299% or more.

(6) In the cross line H / 2.7, the determination can be made in the range of the offset amount from 0.1 mm to 1.53 mm.

  When the offset amount is 0.1 mm, the weldability is easy at 106.6% or less, and weldability is difficult at 106.64% or more.

  Judgment when the offset amount is 1.53 mm is easy to weld at 270% or less, and difficult to weld at 278% or more.

(7) In the cross line H / 2.6, the determination can be made within the range of the offset amount from 1.5 mm to 1.56 mm.

  When the offset amount is 1.5 mm, the weldability is easy at 260% or less, and weldability is difficult at 261% or more.

  When the offset amount is 1.56 mm, the weldability is easy at 268% or less, and weldability is difficult at 269% or more.

(8) Cannot be determined when cross line H / 2.5 and denominator is 2.5 or less.

  FIG. 27 shows a graph of the above results. In the graph shown in FIG. 27, the weldability can be determined if it is within the range indicated by hatching.

1A, 2A, 3A Band saw blades T1-T8 Sawtooth GA Galette TB Tooth bottom (bottom)
A, B area RF1 first flank RF2 second flank

Claims (10)

  A band saw blade comprising an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as a single saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the tooth of the straight tooth. A first flank face from the front, and a second flank face connected to the bottom face of the galette in the succeeding tooth behind the straight tooth on the rear side of the first flank face. A band saw blade characterized in that, in order to perform endless welding on the flank, the flank angle of the second flank is set to be less than 44 °.   A band saw blade comprising an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as a single saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the tooth of the straight tooth. Provided with a first flank from the front, and on the rear side of the first flank, a second flank comprising a concave curved surface connected to the bottom surface of the galette in the rear teeth of the rear side of the straight tooth, In order to perform endless welding on the second flank, the center position of the second flank is set outside the galette.   A band saw blade comprising an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as a single saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the tooth of the straight tooth. A first flank face from the front, and a second flank face connected to the bottom face of the galette in the succeeding tooth behind the straight tooth on the rear side of the first flank face, In order to provide a third flank between the flank and the second flank, and to perform endless welding on the third flank, the flank angle of the third flank is 0 ° or more and 44 °. Band saw blade characterized by being set to less than.   The band saw blade according to claim 1 or 2, wherein the second flank face is welded in an endless manner.   A band saw blade comprising an appropriate number of straight teeth and an appropriate number of left and right set teeth and right set teeth as a single saw tooth group at an appropriate pitch, wherein at least one straight tooth in the saw tooth group includes the tooth of the straight tooth. A first flank face from the front, and a second flank face connected to the bottom face of the galette in the succeeding tooth on the rear side of the straight tooth on the rear side of the first flank face. A straight line when a straight line parallel to the traveling direction of the band saw blade is drawn through the bottom surface of the galette is defined as G, and a height in the range of H / 2.6 to H / 4.2 from the straight line G is defined as G. The intersection position with the second flank when the parallel line K parallel to the straight line G is drawn is defined as M, and the vertical line perpendicular to the straight line G and the parallel line K from the intersection position M is defined as C. , First and second vertical lines that are equidistant from the vertical line C and parallel to the vertical line C , E, the area surrounded by the vertical line C, the second flank, the first vertical line D and the straight line G is A, and the vertical line C, the flank, the second vertical A band saw blade, wherein area B / area A is equal to or less than a predetermined value, where B is an area surrounded by line E and line G.   6. The band saw blade according to claim 5, wherein an offset distance from the vertical line C to the first and second vertical lines D and E is in a range of 0.1 mm to 1.56 mm. .   The band saw blade according to claim 5 or 6, wherein a value B / A of the area B / area A is in a range of 102% to 292%.   The band saw blade according to any one of claims 1 to 7, wherein a pitch between the straight tooth and the subsequent tooth is a maximum pitch.   The band saw blade according to any one of claims 1 to 8, wherein a galette area between the straight tooth and the succeeding tooth is larger than a galette area of a minimum pitch in the saw tooth group.   The band saw blade according to any one of claims 1 to 9, wherein the number of saw teeth between the straight teeth is 3 or less.

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